StdDevPAggregator (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.sql.execute.VarPAggregator<V>
- - org.apache.derby.impl.sql.execute.StdDevPAggregator<V>

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, Aggregator<V,java.lang.Double,VarPAggregator<V>>
```
public class StdDevPAggregator<V extends java.lang.Number>
extends VarPAggregator<V>
```
This class implements the SQL Standard STDDEV_POP() aggregator, computing a population's standard deviation. It relies on VarPAggregator to compute the population variance and then applies the textbook definition of standard deviation:
```
 √var_pop()
 
```
See Also:

Serialized Form

- Nested Class Summary
  - Nested classes/interfaces inherited from class org.apache.derby.impl.sql.execute.VarPAggregator
    VarPAggregator.Sums
- Field Summary
  
  Fields
  Modifier and Type Field Description
  
  private static long serialVersionUID
  - Fields inherited from class org.apache.derby.impl.sql.execute.VarPAggregator
    count, sums
- Constructor Summary
  
  Constructors
  Constructor Description
  
  StdDevPAggregator()
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  java.lang.Double terminate()
  Return the result scalar value
  - Methods inherited from class org.apache.derby.impl.sql.execute.VarPAggregator
    accumulate, computeVar, init, merge, readExternal, writeExternal
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - serialVersionUID
```
private static final long serialVersionUID
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - StdDevPAggregator
```
public StdDevPAggregator()
```
- Method Detail
  - terminate
```
public java.lang.Double terminate()
```
    Description copied from interface: Aggregator
    
    Return the result scalar value
    
    Specified by:
    
    terminate in interface Aggregator<V extends java.lang.Number,java.lang.Double,VarPAggregator<V extends java.lang.Number>>
    
    Overrides:
    
    terminate in class VarPAggregator<V extends java.lang.Number>